Variable condenser



y 2, 1939- s. YCOH EN 2,156,449

VARIABLE CONDENSER Filed June 13, 1935 H8888! I HHHH! 5G 5 INVENTOR 68 6 54 7 Samuel Cohen ATTORNEYS Patented May 2, 1939 I I UNITE) STATES PATENT OFFICE VARIABLE CONDENSER Samuel Cohen, Brooklyn, N. Y.

Application June 13, 1935, Serial No. 26,379

Claims. (01. 175-415) This invention relates to electrical condensers, Fig. 2 is an inverted plan view of the condenand more particularly to variable-condensers. ser; Inmy co-pending application, Serial No.-26,378 Fig. 3 is a fragmentary section taken in eleflled June 13, 1935, I have disclosed an improved vation in the plane of the line 3-4 of Fig. 1;- and 5 variable condenser in which the stator is secured Fig. 4 shows one of the stator support mem- 5 to'the frame of the condenser by soldering tobers with integrally formed circuit connection gether adjacent metallic parts while holding the lug. stator in exact desired position relative to the Referring to the drawing, the condenser com-' rotor. This construction avoids strain and prises a frame F, a plurality of rotors. R oscil-. deformation of the stator such as arises when latably mounted therein, and'a plurality of sta- 10 the stator is secured in place by tightening aptors S fixedly mounted therein. The stators are propriate mounting screws or the like. The prisecured within the frame by a support system mary object of the present invention is to genwhich is partially metallic and partially insuerally improve condensers having soldered stator lation, in order to insulatedly support the stasupports as aforesaid. tors. The insulation pieces" forming a part oi the 15 A more particular object of my invention resupport system are indicated at l2. The metalsides in the provision of a condenser in which lie parts of the support system include parts all of the soldered points v for supporting the brought close together and secured by solder, as stators are simultaneously accessible through one is indicated at the points H. It will. be noted side of the condenser or in one direction. With from examination of the drawing that the 501- 20 this arrangement the condenser may be suitably dered pieces I4 all face in one. direction, spedisposed to facilitate the application of solder ciflcally the bottom of the condenser; and that from above and all of the points to be soldered the bottom of the condenser is entirely open, may be treated simultaneously. Still another obthereby fully and simultaneously exposing all ject is to so relate the adjacent metal parts of the of the points to be soldered. 'By inverting the support system which are to be soldered that the condenser during the soldering operation, the stator is universally movable relative to the solder may be conveniently applied from above. frame for proper adjustment prior to the solder- The inverted position of the condenser is any ing operation. In accordance with still another way convenient because of the nature of the jig feature and object of my invention, the parts to or fixture employed for properly spacing and 30 be soldered include solder receiving pockets near relatively locating the stator and rotor plates the bottom of the condenser, which pockets all preliminary to and during the soldering operaface upwardly when the condenser is inverted tion. I V and which not only facilitate the soldering opera- Considering the condenser in greater detail, tion but confine the solder, reduce the amount of the frame F comprises end plates l6 and I8 and solder necessary, and increase the strength of partition plates 20 and 22, all arranged in spaced the resulting connection. Other objects of my parallel relation and rigidly secured together by invention center about the frame of the con-' sturdy spacer bars 24. In the present case these denser and are to provide a frame which will be bars are solid and cylindrical and are. grooved fully open at the bottom, therebyfacilitating the as indicated at 26 to receive notches or slots 28 40 soldering of the stators; which will be sturdy and cut into theside edges of the end and partition -rigid,. despite the absence of a bottom wall; and plates. These parts are fitted together with a which will include appropriate provision for comforce-fit and requireno additional means to sepensator or trimmer condensers. cure the same together. I v To the accomplishment of the foregoing and The end and partition plates are further in- 45 other objects which will hereinafter appear, my terlocked by upright strips 30 which areset into invention consists in the variable condenser elemating or receptive slots cut upwardly from the ments and their relation one to the other as are bottom edges of the end and partition plates, hereinafter more particularly described in the The top edge of strip 30 is itself slightly recessed specification and sought to be defined in the or notched as is best shown at 32 in Fig. 3, there'- 50 claims. The specification is accompanied by a by establishing the desired location or spacing of drawing in which: I the end and partition plates. The bottom edge Fig. 1 is a transverse section through the conof strip 30 is also preferably indented or upwardly denser taken in the plane of the line l-| of notched, as is indicated at 34, and the bottom 2; edges of the end and partitionplates are staked course may .be shaped in a variety of ways. These pieces are riveted to strips 30 by appropriate rivetsqfl. They in turn carry stator support members best shown in Fig. 4 of the drawing. These support .members have horizontal support fl'ngersf' lkformed integrally therewith and the tips for fingers 44 are preferably turned upwardly. Some of the waste metal between fingers 44 may; befappropriately shaped and struck in opposite directions to form the circuit connection lug 48. The insulation pieces I! are slotted at 50 to receive support fingers 44 and the complete suppbrt fl is rigidly locked in place by appropriate rivets 52. It will be noted that'the body of support 42 is located outside the insulation piece l2 and this isof advantage, first, in providing access to circuit connection lug 48 and secondly, and more importantly, in providing an excellent connection for the adjustable plate 54 of a suitable trimmer or compensator condenser.

The rotors R need no detailed description, being conventional in construction and each comprising a plurality of plates 56 held in. spaced parallel relation on a suitable rigid rotor shaft 58, one end 68 of which projects through the forward end plate of the frame. The rotor shaft 58 is suitably journaled in the frame as by the use of a series or raceway of ball bearings at 62 in forward end plate l6, and a single thrust ball bearing at 64, this bearing being supported by an adjustable plate 66 held on rotor end plate l8 by screws 68. The partition plates 20 and 22 are downwardly notched or cutaway as shown at 10 in Fig. 1, thereby clearing the rotor shaft. Contact between the rotor and frame and circuit connections to the rotor sections may be made by means of conventional forked contact springs I2, one of which is shown in Fig. 1. These springs have been-omitted in Fig. 2 in order not to unnecessarily complicate the drawing, but it will be understood that one spring may be and preferably is used for each condenser section.

The stators S each comprise a plurality of stator plates 14 v which are held assembled in spaced parallel relation by appropriate spacer straps or combs generally designated by the numeral 16. Each spacer 16 includes an upper strap 18 and a lower strap secured to the stator plates by appropriate'staked tongue and slot connections 82. The straps l8 and 80 are preferably disposed at an angle and spaced about the periphery of the stator plates and are interconnected by outwardly pressed channels including a top wall 84, a sidewall 86 and a bottom wall 88. The bottomwall .88 is preferably horizontally disposed and is desirably indented at 98 to form solder pockets located directly above the tips 48 of the support fingers 44. tips 48 preferably project into solder pockets 9!), as is clearly shown in Fig. 1, but there is preferably no'direct contact therebetween which might interfere with universal movement or adjustability of the stator prior to the soldering operation.

In practice the rotor shaft is secured in place and properly adjusted before. the stators are soldered. The condenser is then placed in a suitable jig or fixture which operates to accurately center and space the stators relative to the rotors. The condenser is preferably in inverted position.

In fact, the upwardly turned While the stators are thus accurately positioned in desired location, solder is applied to the solder pockets 90 and heated, thereby forming the soldered connections l4 previously referred to. In Fig. 2 some of the connections are shown soldered and others have been left open. This showing is made solely for purposes of illustration and it will be understood that in actual practice all of the soldered connections H are preferably formed at one and the same time. To avoid the pressure of soldering irons or the like on the parts of'the condenser, the soldered joints may be formed by directing a plurality of properly spaced jets of flame against the soldering pockets after preliminarily placing a small piece or measure of solder at each pocket. The flames melt the bits of solder all at one time, thereby forming all of the soldered connections simultaneously. With this treatment, the use of the solder pockets 90 is especially convenient, forjit automatically localizes the applied solder and keeps it from running to other parts of the condenser where it is not desired and might even prove injurious. Of course the pockets are also of value in strengthening the soldered connections, in providing a maximum of soldered surface with a minimum of solder, and in affording universal adjustment of the stator relative to the frame during the soldering operation. I

The condenser may be provided with appropriate compensator or trimmer condensers and these are formed by the provision of a stamped sheet metal plate 54, the upper end. 92 of which is riveted to the stator support 42 and insulation piece I2 by the same rivets 52 asare used even whenno trimmer is employed. The lower end 94 of the trimmer plate acts as a condenser surface and is connected to the upper end 92 by an outwardly bent portion 96 which adds flexibility to the plate. A suitable piece of insulation, prefer ably a mica strip 98, is placed between the trimmer plate 94 and the frame strip 30 of the condenser. The trimmer plate is adjusted by an appropriate screw I80 bearing against the insulation washer I02 and passing through -a large hole H14 in the plate; The screw is threadedly received in a threaded hole I03 'inst'rip 30,. The outwardly bent portion 96 of the trimmer plate 54 is slotted or cut away at 95 to clear the outwardly projecting circuit connection lug 48. 1 a

It is believed that the mode of constructing and assembling as well as the many advantages of my improved variable condenser with soldered stator support will be apparent from the foregoing detailed description thereof. It will also be apparent that while I have shown" and described my lnvention in a preferred form, many changes and modifications may be made in the' plates and outwardly channeled spacer straps holding the same-in spaced parallel relation, a

wall of said channels being indented upwardly to form solder pockets, metallic stator supporting fingers insulatedly mounted on said condenser frame and projecting inwardly to points beneath the solder pockets and there turned upwardly into said solder pockets, the union between the supporting fingers andv the spacer straps being made by solder received in said solder pockets, thereby providing a strain free stator mounting.

2. A variable condenser comprising a frame, a rotor mounted therein, a stator including stator plates and outwardly channeled spacer straps holding the same in spaced parallel relation, the bottom wall of said channels being substantially horizontal and being indented upwardly to form solder pockets, metallic stator supporting fingers insulatedly mounted on said condenser frame and projecting inwardly to points beneath the solder pockets, the bottom of the condenser frame being open to accessibly expose all of said solder pockets, the union between the supporting fingers and the spacer straps being made by solder received in said solder pockets, thereby providing a strain free stator mounting.

3. A variable condenser comprising a frame including end and partition plates held in spaced parallel relation by bars, rotor sections mounted in said frame, cooperating stator sectionseach including a plurality of plates held in spaced parallel relation by outwardly channeled spacer straps, the bottom walls of the channels being indented upwardly to form solder pockets, insulation pieces secured to bars of the frame, metallic stator supports secured to said insulation pieces and projecting inwardly to points directly beneaththe solder pockets, the union between the stator supports and the spacer straps being'rnade by solder received in said solder pockets, thereby providing a strain free stator mounting.

4. A variable condenser comprising a frame including end and partition plates held in spaced parallel relation by solid round bars grooved to receive slots in the sides of the plates, and strips set edgewise into mating slots at the lower edges of the plates, rotor sections mounted in said frame, cooperating stator sections each including a plurality of plates held in spaced parallel relation by spacer straps, the bottom Walls of the straps being indented upwardly to form solder pockets, insulation pieces secured to the frame strips and projecting upwardly therefrom, metallic stator supports secured to said insulation pieces and including support fingers projecting inwardly to points directly beneath the solder pockets, the union between the stator supports and the spacer straps being made by solder received in said solder pockets, thereby providing a strain free stator mounting.

5. A variable condenser comprising a frame, a rotor mounted therein, a stator including stator plates and outwardly channeled spacer straps holding the same in spaced parallel relation, as wall of said channels being indented upwardly to form solder pockets, metallic stator supporting fingers insulatedly mounted on said condenser frame and projecting inwardly to points beneath the-solder pockets, the union between the sup porting fingers and the spacer straps being made by solder received in said solder pockets, thereby providing a strain free stator mounting.

. SAMUEL com. 

